<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>闰年判断</title>
    <script>
      function isLeapYear(year) {
        //判断 - 可以整数4,但是不能整除100或者可以被400整除
        return (year % 4 == 0 && year % 100 != 0) || year % 400 == 0
      }
    </script>
  </head>
  <body></body>
</html>
